Stainless Steel 7Cr17MoV
GB 7Cr17MoV
7Cr17MoV is a molybdenum- and vanadium-modified high-carbon 17 % Cr martensitic stainless steel, broadly equivalent to 440A, with better toughness and edge retention than plain 7Cr17.
Reference datasheet — 7Cr17MoV is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the QT55-57 condition
7Cr17MoV tempers and conditions
7Cr17MoV is supplied in 7 conditions, soft to hard. QT55-57 is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Mill-supply condition for blanking, stamping and machining before hardening. | 420 | 740 | 20 | 210 HB | — |
Cold Rolled + Annealed strip | The standard 0.8–4 mm knife-blank strip form sold by Chinese mills. | 420 | 730 | 20 | 17 HRC | 3.1 % IACS |
Hot Rolled + Annealed | Thicker plate/bar stock for large blades and tooling, softened for sawing and milling. | 430 | 760 | 18 | 20 HRC | 3.1 % IACS |
Q&T 50–52 HRC | Tougher setting for large choppers, machetes and tools where chipping matters more than edge life. | 1,500 | 1,700 | 7 | 51 HRC | — |
Q&T 53–55 HRC | Common kitchen-knife hardness: easy to re-sharpen, good toughness, moderate edge retention. | 1,620 | 1,850 | 5 | 54 HRC | — |
QT55-57Default Q&T 55–57 HRC | Default finished-blade condition for Chinese folders and outdoor knives: best balance of edge holding and chip resistance. | 1,700 | 1,950 | 4 | 56 HRC | — |
Q&T + Cryo 57–59 HRC | Sub-zero treated maximum-hardness setting for razor-type edges; noticeably more brittle and prone to edge chipping. | 1,780 | 2,050 | 2.5 | 58 HRC | — |
What is 7Cr17MoV?
7Cr17MoV is a molybdenum- and vanadium-modified high-carbon 17 % Cr martensitic stainless steel, broadly equivalent to 440A, with better toughness and edge retention than plain 7Cr17. Hardened and tempered it reaches about 1700 MPa yield, 1950 MPa tensile, 4 % elongation and 56 HRC, and it is bought mainly as cold-rolled blade strip and blanks for folding and kitchen knives. Corrosion resistance is moderate (score 55), maximum service temperature is 400 °C, and machinability drops to a score of 8 once hardened, so all cutting must be done annealed. Consider 440C where higher wear resistance is needed. 7Cr17MoV has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,370°C (2,498 °F). 7Cr17MoV has a yield strength of 1,700 MPa (247 ksi) and a tensile strength of 1,950 MPa (283 ksi) — stronger than 100% of stainless steel grades. Elongation at break is 4% and the elastic modulus is 200 GPa (29 Msi).
What is 7Cr17MoV used for?
- pocket knives
- kitchen cutlery
- outdoor blades
Advantages
- High strength — 1,700 MPa (247 ksi), better than 100% of stainless steel grades
- Polishes to a fine finish — 82/100, better than 95% of stainless steel grades
- Low embodied carbon — 3.2 kg CO₂/kg, better than 95% of stainless steel grades
- High electrical conductivity — 2.9 % IACS, better than 87% of stainless steel grades
- Conducts heat well — 24 W/m·K (13.9 BTU/hr·ft·°F), better than 81% of stainless steel grades
Limitations
- Limited ductility — 4%, worse than 100% of stainless steel grades
- Low fracture toughness — 22 MPa·√m (20 ksi·√in), worse than 100% of stainless steel grades
- Difficult to machine — 8/100, worse than 100% of stainless steel grades
- Limited formability — 5/100, worse than 99% of stainless steel grades
- Difficult to weld — 15/100, worse than 98% of stainless steel grades
7Cr17MoV properties
Typical room-temperature values for 7Cr17MoV-QT55-57; bars are the position among stainless steel grades.
Physical3
7Cr17MoV has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Mechanical15
7Cr17MoV has a yield strength of 1,700 MPa (247 ksi) and a tensile strength of 1,950 MPa (283 ksi) — stronger than 100% of stainless steel grades. Elongation at break is 4% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
7Cr17MoV is rated for continuous service to 400°C (752 °F). It conducts heat at 24 W/m·K (13.9 BTU/hr·ft·°F), better than 81% of stainless steel grades. Thermal expansion is 10.2 µm/m·K (5.67 µin/in·°F).
Electrical3
7Cr17MoV conducts electricity at 2.9 % IACS, better than 87% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 71% of stainless steel grades.
Sustainability4
Producing a kilogram of 7Cr17MoV takes about 48 MJ of energy and emits 3.2 kg of CO₂ — less than 85% of stainless steel grades. Typical recycled content is 45%.
Manufacturability7
7Cr17MoV's machinability is not recommended (8/100, worse than 100% of stainless steel grades); weldability poor (15/100); formability not recommended (5/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. 7Cr17MoV is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 7Cr17MoV
Is 7Cr17MoV easy to machine?
Machine, drill and blank only in the annealed state with sharp carbide tooling and rigid setups; after hardening it is grind/EDM/laser only, and grinding must be wet to avoid burning the edge.
Can 7Cr17MoV be welded?
Essentially not a welding grade — high carbon martensite cracks; if a tang must be joined, preheat 250–300 °C, use austenitic 309/310 filler and temper immediately after.
Can 7Cr17MoV be formed, bent or molded?
Blank, punch and profile in the annealed condition (bend radii ≥2t); harden at 1030–1070 °C, quench in oil or forced gas, optional −70 °C cryo, then temper 150–200 °C (avoid 400–550 °C temper embrittlement/corrosion loss).
7Cr17MoV chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Chigh carbon for martensite hardness + Cr carbides | 0.6 – 0.75 | 0.7 |
| Si | ≤ 1 | 0.4 |
| Mn | ≤ 1 | 0.5 |
| Pimpurity limit | ≤ 0.04 | |
| Simpurity limit | ≤ 0.03 | |
| Crprovides stainless passivity | 16 – 18 | 17 |
| Mopitting resistance and temper strength | 0.3 – 0.75 | 0.5 |
| Vgrain refinement, fine carbides for edge retention | 0.07 – 0.3 | 0.15 |
| Niresidual | ≤ 0.6 | |
| Fe | balance |
What surface finishes work on 7Cr17MoV?
Takes a fine satin or mirror polish; passivate in nitric or citric acid after grinding, and PVD/black-oxide or stonewash finishes are common on knife blades — do not anodize.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel 7Cr17MoV in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- 440A
How much does 7Cr17MoV cost?
7Cr17MoV is a standard-cost stainless steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
7Cr17MoV — frequently asked
What is 7Cr17MoV used for?
7Cr17MoV is typically used for pocket knives, kitchen cutlery and outdoor blades. In short: 440A-class blade steel; better edge holding than 7Cr17; grind-only after hardening.
What is the yield strength of 7Cr17MoV?
7Cr17MoV has a typical yield strength of 1,700 MPa (247 ksi) and a tensile strength of 1,950 MPa (283 ksi) — stronger than 100% of stainless steel grades. Strength varies by condition: see the 7 listed tempers.
Is 7Cr17MoV easy to machine?
Not especially — machinability is rated not recommended (8/100, worse than 100% of stainless steel grades). Machine, drill and blank only in the annealed state with sharp carbide tooling and rigid setups; after hardening it is grind/EDM/laser only, and grinding must be wet to avoid burning the edge.
Can 7Cr17MoV be welded?
Not readily — weldability is rated poor (15/100). Essentially not a welding grade — high carbon martensite cracks; if a tang must be joined, preheat 250–300 °C, use austenitic 309/310 filler and temper immediately after.
What surface finishes work on 7Cr17MoV?
Takes a fine satin or mirror polish; passivate in nitric or citric acid after grinding, and PVD/black-oxide or stonewash finishes are common on knife blades — do not anodize.
Can 7Cr17MoV be formed, bent or molded?
Blank, punch and profile in the annealed condition (bend radii ≥2t); harden at 1030–1070 °C, quench in oil or forced gas, optional −70 °C cryo, then temper 150–200 °C (avoid 400–550 °C temper embrittlement/corrosion loss).
What is the maximum service temperature of 7Cr17MoV?
7Cr17MoV is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 7Cr17MoV QT55-57 and 7Cr17MoV-A?
QT55-57 is the default condition — default finished-blade condition for Chinese folders and outdoor knives: best balance of edge holding and chip resistance. A: mill-supply condition for blanking, stamping and machining before hardening. Yield strength is 1,700 MPa in QT55-57 versus 420 MPa in A.
How much does 7Cr17MoV cost?
7Cr17MoV is a standard-cost stainless steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- GB/T 1220 (martensitic 7Cr17 family) (2007)
- ASTM A276/A276M — Stainless Steel Bars and Shapes (Type 440A) — ASTM International (2017)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (martensitic stainless steels) — ASM International (1991)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.